5 files changed, 222 insertions, 0 deletions
diff --git a/storage/error.go b/storage/error.go
new file mode 100644
index 0000000..956a564
--- /dev/null
+++ b/storage/error.go
@@ -0,0 +1,5 @@
+package storage
+
+import "errors"
+
+var NotFoundError = errors.New("link not found")
+\ No newline at end of file
diff --git a/storage/link.go b/storage/link.go
new file mode 100644
index 0000000..f334f42
--- /dev/null
+++ b/storage/link.go
@@ -0,0 +1,63 @@
+package storage
+
+import (
+	"encoding/json"
+	"errors"
+	"github.com/google/uuid"
+	"time"
+)
+
+type Link struct {
+	Id        uuid.UUID
+	Target    string
+	OpensFrom time.Time
+	OpensLeft int
+}
+
+var Null = uuid.UUID{}
+
+func (l Link) Save(storage Storage[Link, uuid.UUID]) (uuid.UUID, error) {
+	return storage.Save(l)
+}
+
+func (l Link) Serialize() ([]byte, error) {
+	return json.Marshal(l)
+}
+
+func (l Link) Use() error {
+	if e := l.Valid(); e != nil {
+		return e
+	}
+
+	remaining := l.OpensLeft - 1
+	if remaining < 1 {
+		_ = Current.Delete(l)
+		return nil
+	}
+	n := Link{
+		Id:        l.Id,
+		Target:    l.Target,
+		OpensFrom: l.OpensFrom,
+		OpensLeft: remaining,
+	}
+	return n.Update(Current)
+}
+
+func (l Link) Update(storage Storage[Link, uuid.UUID]) error {
+	return storage.Update(l)
+}
+
+var NoOpensError = errors.New("no opens left")
+var NotYetOpenError = errors.New("not yet open")
+
+func (l Link) Valid() error {
+	if l.OpensLeft < 1 {
+		return NoOpensError
+	}
+
+	if time.Now().Before(l.OpensFrom) {
+		return NotYetOpenError
+	}
+
+	return nil
+}
diff --git a/storage/saveable.go b/storage/saveable.go
new file mode 100644
index 0000000..46a53f2
--- /dev/null
+++ b/storage/saveable.go
@@ -0,0 +1,7 @@
+package storage
+
+type Saveable[K comparable] interface {
+	Save(storage Storage[Saveable[K], K]) (K, error)
+	Update(storage Storage[Saveable[K], K]) (K, error)
+	Serialize() ([]byte, error)
+}
diff --git a/storage/sqlite/sqlite.go b/storage/sqlite/sqlite.go
new file mode 100644
index 0000000..9372828
--- /dev/null
+++ b/storage/sqlite/sqlite.go
@@ -0,0 +1,132 @@
+package sqlite
+
+import (
+	"database/sql"
+	"delayed.link/storage"
+	"encoding/json"
+	"errors"
+	"github.com/google/uuid"
+	_ "github.com/mattn/go-sqlite3"
+	"github.com/spf13/pflag"
+	"log"
+)
+
+var (
+	dbFile = pflag.StringP("dbfile", "d", "delayedlink.db", "")
+)
+
+type SqliteStorage struct {
+	*sql.DB
+}
+
+func (s *SqliteStorage) Close() error {
+	return s.DB.Close()
+}
+
+func (s *SqliteStorage) Save(item storage.Link) (uuid.UUID, error) {
+	stmt, err := s.Prepare("INSERT INTO links VALUES (?, ?)")
+	if err != nil {
+		return storage.Null, err
+	}
+	id := uuid.New()
+	item.Id = id
+	obj, err := item.Serialize()
+	if err != nil {
+		return storage.Null, err
+	}
+	_, err = stmt.Exec(id, obj)
+	if err != nil {
+		return storage.Null, err
+	}
+	return id, nil
+}
+
+const insertStatement = `SELECT (obj) FROM links WHERE id = ? LIMIT 1`
+
+func (s *SqliteStorage) Load(key uuid.UUID) (*storage.Link, error) {
+	stmt, err := s.DB.Prepare(insertStatement)
+	if err != nil {
+		return nil, err
+	}
+	rows, err := stmt.Query(key.String())
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var link *storage.Link
+	var data []byte
+	if !rows.Next() {
+		return nil, storage.NotFoundError
+	}
+	err = rows.Scan(&data)
+	if err != nil {
+		return nil, err
+	}
+	err = json.Unmarshal(data, &link)
+	if err != nil {
+		return nil, err
+	}
+
+	return link, nil
+}
+
+const creation_sql = `CREATE TABLE IF NOT EXISTS links (
+    id UUID PRIMARY KEY,
+    obj JSONB NOT NULL
+);`
+
+func New() *SqliteStorage {
+	db, err := sql.Open("sqlite3", *dbFile)
+	if err != nil {
+		log.Panic(err)
+	}
+
+	_, err = db.Exec(creation_sql)
+	if err != nil {
+		panic(err)
+	}
+
+	return &SqliteStorage{
+		db,
+	}
+}
+
+const deleteQuery = `DELETE FROM links WHERE id = ?`
+
+var NotFoundError = errors.New("entry not found")
+
+func (s *SqliteStorage) Delete(item storage.Link) error {
+	stmt, err := s.DB.Prepare(deleteQuery)
+	if err != nil {
+		return err
+	}
+	res, err := stmt.Exec(item.Id)
+	if err != nil {
+		return err
+	}
+	if aff, err := res.RowsAffected(); aff < 1 || err != nil {
+		if err == nil {
+			return NotFoundError
+		}
+		return err
+	}
+	return nil
+}
+
+const updateQuery = `UPDATE links SET obj = ? WHERE id = ?`
+
+func (s *SqliteStorage) Update(item storage.Link) error {
+	stmt, err := s.DB.Prepare(updateQuery)
+	if err != nil {
+		return err
+	}
+	obj, err := item.Serialize()
+	if err != nil {
+		return err
+	}
+	_, err = stmt.Exec(item.Id, obj)
+	if err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/storage/storage.go b/storage/storage.go
new file mode 100644
index 0000000..94d7056
--- /dev/null
+++ b/storage/storage.go
@@ -0,0 +1,15 @@
+package storage
+
+import (
+	"github.com/google/uuid"
+)
+
+type Storage[T any, K comparable] interface {
+	Save(item T) (K, error)
+	Update(item T) error
+	Load(key K) (*T, error)
+	Delete(item T) error
+	Close() error
+}
+
+var Current Storage[Link, uuid.UUID]